Methods for facilitating circuit board processing

ABSTRACT

A circuit board carrier and method of using the same. The carrier allows circuit boards to be processed on lead frame-based semiconductor processing equipment. The circuit board carrier contains a structure to secure a circuit board thereto and the carrier is sized and shaped and provided with standardized indexing holes to allow processing of circuit boards on processing equipment configured for lead frame-based processing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 09/873,834,filed Jun. 4, 2001, now U.S. Pat. No. 6,398,043, issued Jun. 4, 2002,which is a continuation of application Ser. No. 09/651,489, filed Aug.30, 2000, now U.S. Pat. No 6,279,758 B1, issued Aug. 28, 2001, which isa continuation of application Ser. No. 09/421,164, filed Oct. 19, 1999,now U.S. Pat. No. 6,158,595, issued Dec. 12, 2000, which is acontinuation of application Ser. No. 09/225,277, filed Jan. 5, 1999, nowU.S. Pat. No. 5,992,649, issued Nov. 30, 1999, which is a continuationof application Ser. No. 08/640,147, filed Apr. 30, 1996, now U.S. Pat.No. 5,911,329, issued Jun. 15, 1999.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to an apparatus and method forfacilitating circuit board processing and, more specifically, to areusable circuit board carrier and method of using same that allowscircuit boards to be processed on conventional semiconductor deviceassembly equipment commonly employed with lead frames.

2. State of the Art

The manufacture of packaged semiconductor devices is a most competitive,high volume industry. Because of its voluminous production nature, evenminute improvements in manufacturing efficiency and/or quality can makea considerable difference in overall manufacturing costs whenaccumulated over hundreds of thousands or even millions of units. Thus,automation of every manufacturing process is essential for one in theindustry to compete, and improving those automated processes to makethem more efficient and produce fewer defects is necessary to staycompetitive.

Automation requires large capital expenditures in automatedmanufacturing and processing equipment. Moreover, such automatedequipment is typically configured to process a specific component orcomponent type having a particular standardized configuration, usuallyto the exclusion of other types of components. For example, dedicatedequipment is purchased for fabrication of packaged semiconductor deviceswherein a semiconductor die is mounted to a lead frame, wire-bondedthereto, encapsulated by transfer molding and then trimmed and formed toremove mold flashing and extraneous lead frame strip elements and formthe external ends of the lead frame leads. Adaptability of at least someof such equipment, however, to accommodate another type of assembly,such as a printed circuit board assembly, would increase the value ofthe capital investment by providing greater opportunity for use andmanufacturing flexibility.

One way to increase efficiency in the manufacturing of semiconductordevices is to process the devices in batches. Batch processing allows agroup of components to be indexed through a given process station ingreater numbers compared to throughputting single components, andresults in more efficient utilization of the processing equipment. Thus,processing equipment is typically configured to perform one or moreoperations on a number of devices in a single cycle, creating fasterprocessing cycle times and a lower cost per unit.

In order to accommodate batch processing in the manufacturing ofpackaged semiconductor devices, it is known in the art to form severalsimilar components together as a unit for processing. For example, leadframes are typically formed as a linear lead frame strip comprised ofseveral lead frames joined together at their peripheries. Thus, all ofthe lead frames in a lead frame strip can be substantiallysimultaneously processed by the addition of dice, subsequent wirebonding, and finally encapsulation to form several packagedsemiconductor devices, which are separated in a final trim and formoperation, as previously described.

Lead frame strips commonly employ relatively robust longitudinal railsegments along each edge to stiffen the strip and provide indexing holesfor manipulation of the strip within and between processing stations.Lead frames may also be provided with a carrier that not only providesstructural support for the lead frame strip during processing, but isadapted to be indexable and/or conveyable by the manufacturingequipment. For example, in U.S. Pat. No. 5,111,935, a universal leadframe carrier is disclosed to hold individual strips of lead framestogether with their respective chips for bonding. The lead frame carriercan then be used to systematically move the lead frame from station tostation during manufacture. U.S. Pat. 4,554,404 discloses another leadframe support. Magazines, such as disclosed in U.S. Pat. No. 4,910,886,may be employed to transport or store a large number of lead framestrips, with or without carriers.

Because of the advantages of batch processing and workpiece handlingtechniques employed in the manufacture of packaged semiconductor devicesand, more particularly, to the processing of lead frame-based devices,such processing would also be beneficial in the manufacture of devicesusing printed circuit boards or other conductive trace-carryingsubstrates to which semiconductor dice are mounted and electricallyconnected. Conventional equipment used in the processing of packagedsemiconductor devices, however, is typically configured to accommodatelead frame strips and/or packaged semiconductor devices based upon leadframes and is, therefore, not employable in the manufacture of printedcircuit board assemblies and the like. Such equipment used in themanufacture of lead frame-based semiconductor devices (e.g., dieattachers, wire bonders, drop dispensers and various lead framemagazines) would, however, be useful for the processing of printedcircuit boards and other planar die supports, such as ceramicsubstrates, if a means could be formed to do so. Moreover, utilizationof assembly equipment for more than one type of product wouldsignificantly reduce capital expenditures necessary for semiconductormanufacturing of different types of assemblies.

Different approaches have been employed for handling printed circuitboards, as disclosed in U.S. Pat. Nos. 3,915,307; 3,930,644; 4,109,379;4,155,447; 4,198,024; 4,291,867; 4,385,781; 4,600,231; 4,763,782;4,953,061; 5,339,221; 5,406,455; and 5,456,402. However, the foregoingpatents are largely directed toward storage or transport of boards, inmost instances are directed toward boards of substantial size, such asmother boards, are intended for installation of boards in chassis orother higher-level packaging for operational purposes, or are notadaptable to automated handling on a high-volume basis.

U.S. Pat. No. 5,044,615 discloses a printed circuit board holder adaptedto retain a plurality of boards with a cam-type mechanism interposedbetween boards located in laterally and longitudinally adjacent recessesin the holder. The holder is not suitable in size or configuration foruse with lead frame assembly processing and transport equipment, and maynot provide the close locational tolerances necessary for use ofdie-attach and wirebonding equipment.

Thus, it would be advantageous to provide a reusable circuit boardcarrier and method of using same that allows circuit boards to beprocessed on conventional lead frame-based semiconductor device assemblyequipment.

BRIEF SUMMARY OF THE INVENTION

According to the present invention, a reusable circuit board carrier andmethod of using same is provided to allow circuit boards to be processedon conventional lead frame-based semiconductor device assemblyequipment. More specifically, the circuit board carrier providesstructure for temporarily aligning and securing a circuit board theretofor handling, storage and processing and allows the circuit board to beremoved and replaced by another circuit board after processing has beencompleted. Moreover, the circuit board carrier may accommodate one ormore circuit boards simultaneously in the same manner that multiple leadframes are manipulated together as a lead frame strip.

In a preferred embodiment, the circuit board carrier is comprised of anelongate, substantially planar member having a relatively thincross-section and a generally rectangular perimeter. The circuit boardcarrier includes one or more board abutment surfaces for aligning atleast one circuit board relative to the carrier, as well as structurefor immobilizing and holding the aligned circuit board relative to thecarrier. The abutment surfaces may include protrusions extending fromthe attachment surface of the circuit board carrier, the protrusionshaving various configurations for abutting flat or contoured edgesurfaces of the circuit board. In addition, the immobilizing structuremay include protrusions that extend from the attachment surface over aportion of the attached circuit board, or capture pins that fit throughapertures in the circuit board and the attachment surface to pin theboard to the carrier. Biased abutment surfaces that retract to allowinsertion of a circuit board onto the carrier and then return to theiroriginal position once the circuit board is inserted may also beincorporated.

The carrier of the invention is sized and shaped to be transportedbetween and processed on conventional semiconductor device assemblyequipment and may include longitudinally extending lateral flanges alongits outer edges. In addition, one or both of these flanges may includeindexing holes formed therein to be engaged by transport and indexingdevices. The carrier may also include an isolation member comprised of arelatively thin, substantially rectangular sheet of material, such as astatic dissipative material or other suitable material known in the art,to isolate the circuit board from the carrier.

In another preferred embodiment, the circuit board carrier is comprisedof two substantially parallel, elongate rails, each having groovesformed therein for holding one or more circuit boards. The circuit boardcarrier is provided with structure to keep the circuit board or boardsfrom sliding out of the grooves, such as a transverse member having aninterference fit with the grooves or otherwise secured to the rails(pin, screw, snap-fit, etc.) or a pivotally mounted member securable atits free end to the opposite rail. The circuit board carrier is sizedand shaped to present circuit boards to be processed on conventionallead frame-based semiconductor device assembly equipment and may includeindexing holes along the outer edge of one or both elongate rails toaccommodate typical indexing equipment. The circuit board carrierincludes at least one cross-member for connecting the two railstogether, which may be positioned at an end of the rails to accommodateone or more circuit boards slid into the carrier, or proximate a medialportion of the rails so that one or more circuit boards may be carriedon either side of the cross-member.

As used in the description of the present invention and specifically inthe claims appended hereto, the term “circuit board” is not limited toparticular structures such as conventional FR4 boards, but encompassesany conductor-carrying, substantially planar substrate or other diesupport member formed of any suitable material including, withoutlimitation, conductor-carrying laminates formed of various materials,silicon or glass substrates with deposited (as by photolithography)conductors, ceramic substrates and other suitable conductor carriers asknown in the art. Further, the term circuit board includes andencompasses all types of single- and multi-die assemblies, such asmulti-chip modules (MCMs), including different types of dice or the samedie type, the latter being exemplified by single in-line memory modules(SIMMs) or dual in-line memory modules (DIMMs).

Although the circuit board carrier of the present invention has beendescribed in relation to several preferred embodiments, it is believedthat a major aspect of the invention is that the circuit board carrierallows circuit boards to be processed on conventional lead frame-basedsemiconductor device assembly equipment. This and other features of thepresent invention will become apparent from the following detaileddescription, the accompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is an exploded, perspective view of a first embodiment of acircuit board carrier in accordance with the present invention;

FIG. 2 is a close-up exploded schematic view of a capture pin andassociated circuit board carrier of the embodiment of FIG. 1;

FIG. 3 is a perspective view of the embodiment of the circuit boardcarrier of FIG. 1 in assembled form;

FIGS. 4A and 4B are top and side schematic views, respectively, of asecond embodiment of a circuit board carrier in accordance with thepresent invention;

FIGS. 5A and 5B are top and side schematic views, respectively, of athird embodiment of a circuit board carrier in accordance with thepresent invention;

FIG. 6 is a top schematic view of a fourth embodiment of a circuit boardcarrier in accordance with the present invention; and

FIG. 7 is a top schematic view of a fifth embodiment of a circuit boardcarrier in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a circuit board carrier 10 in an exploded perspective view,circuit board carrier 10 being generally comprised of an elongate,substantially planar member 12 defining an attachment surface 14. Theplanar member 12 has a generally rectangular configuration and is sizedto be indexed through conventional lead frame-based semiconductor deviceassembly equipment, as known in the art. Extending longitudinally alongthe outer edges 16 and 18 of the planar member 12 are two substantiallyparallel flanges 20 and 22, respectively. One or both of the flanges 20and 22 may be provided with a plurality of indexing or tooling holes 24.Such tooling holes 24 are used in the art for workpiece transportpurposes and to position components within an assembly apparatus. It ispreferred that flanges 20 and 22 be formed of a rigid, dimensionallystable material such as spring steel, for example, of 0.010 inchthickness. This is due to the fact that commonly employed circuit boardmaterials such as FR4 are neither dimensionally stable nor robust enoughto accommodate transport and indexing equipment without alignmentproblems and potential damage to the unit. Moreover, the separatelyformed flanges are easily replaceable if worn or damaged, so that anentire circuit board carrier need not be scrapped. The flanges may bemechanically or adhesively secured to the main body of the circuit boardcarrier 10, as in laterally extending grooves cut or otherwise formed inthe sides of planar member 12. Further, the flanges 20 and 22 might beprovided with board position indicators such as notches 25 (brokenlines), holes 27, of a different shape than indexing or tooling holes24, or segments 29 of a different material detectable by a proximitysensor so that the presence and exact location of a particular board(especially useful on a multi-board carrier) is easily determinable bythe wire bonder, die-attach equipment, or other processing apparatus.

Circuit board carrier 10 may be of any suitable length to carry morethan one circuit board, the ultimate length thereof being dictated bythe longest lead frame strip the storage, transport and processingequipment employed with the circuit board carrier is designed toaccommodate (generally under ten (10) inches or 25.40 cm.). Similarly,the width of circuit board carrier 10 is also dictated by existingequipment and is generally, therefore, under two (2) inches (5.08 cm.),the same as a large lead frame strip.

The planar member 12 includes a plurality of board abutment protrusions26, 28, 30, 32, and 34 extending from the attachment surface 14,protrusions 26, 30, 32 (see FIG. 3) and 34 having a generallyrectangular configuration and protrusion 28 having a contouredcross-section to fit a like-contoured edge 36 of a circuit board 38. Theside abutment surfaces of protrusions 26, 28, 30, 32, and 34 are used toalign and maintain the circuit board 38 in exact or precise positionrelative to the planar member 12.

An exemplary circuit board 38, as schematically shown, includes twoapertures 40 and 42 proximate its respective ends 44 and 46. The planarmember 12 also includes apertures 48 and 50 sized, shaped and positionedto be in substantial alignment with the apertures 40 and 42 of thecircuit board 38 when the circuit board 38 is properly positioned on theattachment surface 14. The planar member 12 may also include openings 52and 54 for access to the underside of the circuit board 38.

An isolation member 56 of a dielectric, preferably static-dissipativematerial as known in the art, sized and shaped to fit between thecircuit board 38 and the planar member 12 may also be included inconjunction with the circuit board carrier 10 to isolate the circuitboard 38 from the planar member 12. The isolation member 56 alsoincludes apertures 58 and 60 positioned to align with apertures 40 and42.

To assemble the circuit board carrier 10 with an attached circuit board38, the isolation member 56 is placed on the attachment surface 14followed by the circuit board 38 such that the isolation member 56 andthe circuit board 38 abut the protrusions 26, 28, 30, 32, and 34. Assuch, the apertures 42, 60 and 50 should be in alignment, as shoulderapertures 40, 58, and 48. Capture pin 62 is then inserted into apertures42, 60 and 50 and capture pin 64 inserted into apertures 40, 58, and 48to hold the circuit board 38, isolation member 56 and planar member 12together.

As better shown in FIG. 2, the capture pin 64 (which is substantiallythe same as capture pin 62) includes a cap portion 66 at its proximalend 67, a first substantially semi-cylindrical member 68, and a secondsubstantially semi-cylindrical member 70 extending from the bottomsurface 71 of the cap portion 66. Members 68 and 70 are separated by adiametrically extending compression gap 69. Half-frustoconicalprotrusions 72 and 74 at the distal end of the capture pin 64 extendfrom the semi-cylindrical members 68 and 70, respectively, but have aslightly larger diameter to provide retaining upper edges 76 and 78,respectively, for abutting downwardly facing annular shoulder 80 in thecountersunk base of aperture 48. The first and second substantiallysemi-cylindrical members 68 and 70 extend a distance D equal to thecombined thickness T1 of the circuit board 38, plus the thickness T2 ofthe isolation member 56, plus the thickness T3 of the portion of theplanar member 12 grasped by the half-frustoconical protrusions 72 and74. Thus, when the circuit board carrier 10 is assembled, entry of thehalf-frustoconical protrusions 72 and 74 into aperture 48 squeezes thesubstantially semi-cylindrical members 68 and 70 together to closecompression gap 69 until the half-frustoconical protrusions 72 and 74extend into the counterbore of aperture 48 and upper edges 76 and 78engage the shoulder 80. The half-frustoconical protrusions 72 and 74 fitwholly within the aperture 48 and do not extend below the bottom surface82 of the planar member 12.

FIG. 3 shows the circuit board carrier 10 in assembled form with circuitboard 38 in place. As illustrated, the one end 84 of the circuit board38 abuts the carrier protrusion 26, the contoured edge 36 is abutted bythe carrier protrusion 28, the other end 84 is abutted by carrierprotrusion 30, and the side 86 is abutted by protrusions 32 and 34.Moreover, the circuit board 38 is securely attached to the planar member12 by capture pins 62 and 64, permitting partial or complete inversionof the assembly as desired or required for transport, storage orprocessing.

The circuit board carrier 100 illustrated in FIGS. 4A and 4B is similarto the previously described embodiment, except that a circuit board,such as circuit board 38, may be held in position by inverted L-shapedprotrusions 102 and 104 and biased protrusions 106 and 108. The invertedL-shaped protrusions 102 and 104 extend transversely across the topsurface 110 of the elongate, substantially planar member 112 tolaterally position a circuit board 38 on the planar member 112 withinthe grooves 114 and 116 formed between the L-shaped protrusions 102 and104 and the top surface 110. The biased protrusions 106 and 108 extendupwardly from the top surface 110 and are biased by leaf-type biasingmembers 118 and 120. The biasing members 118 and 120 are positioned incut-outs 122 and 124 and attached at their proximal ends 126 and 128 ina cantilevered fashion to the planar member 112. As shown, biasingmembers 118 and 120 may be formed integrally with planar member 112, andof a reduced thickness in comparison thereto on one or both sides ofplanar member 112 to enhance resiliency. Thus, to secure a circuit boardto the circuit board carrier 100, the biased protrusions 106 and 108 aredepressed to allow lateral passage of the circuit board 38. The circuitboard 38 is then slid into the grooves 114 and 116 until contacted bythe protrusion 130 and biased protrusions 106 and 108 are then allowedto return to their original positions. As with the previously discussedembodiment, the circuit board carrier 100 has the ability to be used forprocessing circuit boards in conventional lead frame-based semiconductordevice assembly equipment. It is also possible to use straight-sidedprotrusions at the locations of L-shaped protrusions 102 and 104 (seebroken lines in FIG. 4B) and to hold a circuit board 38 against thevertical surfaces of the fixed protrusions with biased protrusions 106and 108. Moreover, rather than using leaf-type biasing members such as118 and 120, biased protrusions such as 106 and 108 might be providedwith elastomeric or other (such as coil or bow-spring) biasing elements107 and 109 on their inner faces, so that a circuit board may be droppedbetween the (straight-sided) protrusions, pushed laterally againstbiasing elements 107 and 109, and released, biasing elements 107 and 109then resiliently aligning circuit board 38 against protrusion 130 andbetween L-shaped protrusions at the locations of 102 and 104.

Referring now to FIGS. 5A and 5B, another preferred embodiment of acircuit board carrier 150 is illustrated. The circuit board carrier 150is generally comprised of two longitudinally extending, substantiallyparallel elongate rails 152 and 154. The rails 152 and 154 are held inrelative position to one another by a cross-member 153 secured proximatethe midpoints of the rails 152 and 154. As illustrated, the circuitboard carrier 150 is designed to hold two circuit boards 38. Thoseskilled in the art, however, will recognize that it may be possible toaccommodate a single circuit board 38 by moving the cross-member 153 toone end 155 and shortening the lengths of the rails 152 and 154.Moreover, having rails 152 and 154, as illustrated, with thecross-member positioned at one end 155 would allow two circuit boards 38to be held by the circuit board carrier in a mutually abuttedrelationship.

As better seen in FIG. 5B, each of the rails 152 and 154 has a Y-shapedcross-section including longitudinally extending flanges 156 and 158forming the tail or base of the Yshape and extensions 160, 162 and 164,166 defining longitudinally extending grooves 168 and 170, respectively.The grooves 168 and 170 are sized and shaped to receive a circuit board38 that may be slid therein until abutted by the cross-member 153. Thegrooves 168 and 170 hold the circuit board 38 from all movement, otherthan longitudinal, relative to the circuit board carrier 150. Theflanges 156 and 158 may include a plurality of indexing holes 157 toaccommodate processing on conventional semiconductor assembly equipment.

In order to keep the circuit boards 38 within the circuit board carrier150 without becoming dislodged from the rails 152 and 154, a retainingmember 172 may be secured to the ends 155 and 174 of the circuit boardcarrier 150. Something as simple as a substantially rectangular bar orretaining member 172 forming an interference fit between the grooves 168and 170 at their outer ends may be used to hold circuit boards 38against longitudinal movement relative to the circuit board carrier 150.Thus, to secure the circuit boards 38 within the circuit board carrier150, one circuit board 38 is slid into one end of the grooves 168 and170 to abut cross-member 153 on one side thereof, and another circuitboard 38 is slid into the other end of the grooves 168 and 170 to abutcross-member 153 on the other side thereof. A retaining member 172 ispressed into each end 155 and 174 of the circuit board carrier 150 andthe circuit boards 38 may then be processed through conventionalsemiconductor assembly equipment. Circuit boards 38 are held in exactlongitudinal and lateral alignment for processing, longitudinallythrough their abutment with cross-member 153, and laterally by theconstraining rails 152 and 154. It is contemplated that retainingmembers may be mechanically secured to rails 152 and 154 at 176 byscrews, pins or preferably a snap-lock type mechanism using resilientelements for tool-free insertion and removal. Further, the interior(facing cross-member 153) edges of retaining members 172 may carry anelastomer strip, a leaf spring, or other biasing element 178 tolongitudinally, resiliently maintain circuit boards 38 againstcross-member 153.

The circuit board carrier 180, illustrated in FIG. 6, is substantiallysimilar to the circuit board carrier 150 of FIGS. 5A and 5B, includingY-shaped elongate rails 182 and 184 and cross-member 187. The circuitboard carrier 180, however, includes pivotally mounted, elongateretaining members 186 and 188 at the carrier's ends 190 and 192,respectively. The retaining members 186 and 188 are pivotally mounted torotate in- the plane of the circuit board carrier at their first ends194 and 195, respectively, to the rail 182 by cylindrical pins orprotrusions 196 and 197 or other means known in the art. The second ends198 and 199 of the retaining members 186 and 188 define hooked portions200 and 202, respectively. Locking protrusions or pegs 203 and 205 areattached proximate the proximal and distal ends of the rail 184 toengage with and hold the hooked portions 200 and 202 relative to therail 184 upon inward rotation of the retaining members 186 and 188,respectively. As the retaining members 186 and 188 are rotated to securethe circuit boards 38, biasing members 206 and 208, such as leaf-typesprings attached to the retaining members 186 and 188, respectively, arepressed against the ends 210 and 212 of the circuit boards 38 to forcethe circuit boards 38 toward the cross-member 187. The engagement of thehooked portions 200 and 202 with the pegs 203 and 205 sufficientlysecures the retaining members 186 and 188 to the rail 184 to withstandthe force of the biasing members 206 and 208.

FIG. 7 depicts another alternative circuit board carrier 300, comprisedof a substantially planar member 302, having an upper recess 304 in theupper surface thereof and optional underside recesses 306 to provideaccess to the back of a circuit board 38 disposed in upper recess 304.Planar member 302 includes lateral side rails 308 and 310 extendingcoplanarly therefrom, side rails 308 and 310 including indexing holes24, as previously discussed. Inner lateral surfaces 312 and 314 andinner end surface 316 of upper recess 304 provide alignment surfaces forcircuit board 38, while bow spring 320, abutting inner end surface 322,ensures longitudinal abutment of circuit board 38 against inner endsurface 316. Retainer clip 324 further ensures circuit board securityduring inversion, and may be augmented by retention tabs 326 and 328, ifdesired, extending over circuit board 38 above inner end surface 316.Other arrangements might be employed, such as a resilient elastomerstrip placed along an end surface such as inner end surface 322 insideupper recess 304 in combination with deflectable plastic retention tabsor even strips extending over parts of the periphery of upper recess304. Resilient straps, such as elastomeric bands, may also be placed toextend over portions of the circuit board to which dice are not to bemounted, pulled out of the way during circuit board insertion, andreleased to retain circuit board 38.

It will be further understood and appreciated by those skilled in theart that the present invention, in addition to permitting use of leadframe handling and processing equipment for circuit boards, also affordsadvantages in circuit board yield. Specifically, circuit boards areformed in groups on large dielectric panels, such as panels of FR4. Incircuit boards which are to be handled and processed using the carriersof the invention, no boundaries or other areas on the panel arerequired, as the circuit boards are singulated and placed in thecarriers. Thus, waste or “thiefage” of panel material is virtuallyeliminated. Moreover, with certain designs of the inventive circuitboard carrier wherein substantially the full face of each circuit boardis exposed (no borders being required for holding or handling), morecircuit board “real estate” is available for location of components,circuit traces, and connectors.

In the exemplary embodiments, the circuit board carrier, as illustrated,has an elongated, generally rectangular configuration holding one or twocircuit boards. Those skilled in the art, however, will appreciate thatthe size, shape, number of circuit boards held and/or configuration ofthe carrier may vary to accommodate the type and/or configuration ofassembly equipment through which the carrier is indexed, withoutdeparting from the scope of the present invention. Moreover, thoseskilled in the art will appreciate that there may be other means ofattaching the circuit board to the carrier including modifications andcombinations of the means described herein. It will also be appreciatedby one of ordinary skill in the art that one or more features of theillustrated embodiments may be combined with one or more features fromanother to form yet another combination within the scope of theinvention as described and claimed herein. Thus, while certainrepresentative embodiments and details have been shown for purposes ofillustrating the invention, it will be apparent to those skilled in theart that various changes in the invention disclosed herein may be madewithout departing from the scope of the invention, which is defined inthe appended claims. For example, while the invention has been describedwith reference to certain processing equipment, such as wire bonders anddie-attach machines, it will be appreciated that the invention may alsobe employed with die pick-and-place devices and inverters to effectuateflip-chip die placement on circuit boards in the carriers of theinvention. Furthermore, flex-circuits comprising conductive traces on aflexible dielectric sheet or film (also called TAB tape for TapeAutomated Bonding) may be employed with the invention to electricallyconnect dice to circuit boards disposed in the carriers.

What is claimed is:
 1. A method of fabricating a carrier for securing atleast one circuit board, the method comprising: forming a circuit boardcarrier having a first elongate rail defining a first elongate groovetherein, a second elongate rail substantially parallel to the firstelongate rail defining a second elongate groove therein, and at leastone cross-member connecting the first elongate rail to the secondelongate rail with the first elongate groove facing the second elongategroove; configuring the first elongate groove to receive a first edge ofthe at least one circuit board and the second elongate groove to receivea second, opposing edge of the at least one circuit board; configuringthe first and second elongate grooves in mutually facing relationship tosubstantially constrain non-longitudinal movement of the at least onecircuit board when the first and second edges thereof are respectivelyreceived therein; and securing a biasing member proximate a first end ofat least one of the first and second elongate rails.
 2. A method offabricating a carrier for securing at least one circuit board, themethod comprising: forming a circuit board carrier having a firstelongate rail defining a first elongate groove therein and a secondelongate rail substantially parallel to the first elongate rail defininga second elongate groove therein; positioning at least one cross-membersubstantially between a first end of the first and second elongate railsand a second end of the first and second elongate rails to connect thefirst elongate rail to the second elongate rail, wherein the firstelongate groove faces the second elongate groove; configuring the firstelongate groove to receive a first edge of the at least one circuitboard and the second elongate groove to receive a second, opposing edgeof the at least one circuit board; configuring the first and secondelongate grooves in mutually facing relationship to substantiallyconstrain non-longitudinal movement of the at least one circuit boardwhen the first and second edges thereof are respectively receivedtherein; and securing a first circuit board retaining member proximate afirst end of at least one of the first and second elongate rails.
 3. Themethod of claim 2, further comprising securing a second circuit boardretaining member proximate the second end of at least one of the firstand second elongate rails.
 4. The method of claim 3, wherein thesecuring the second circuit board retaining member comprises securing abiasing member.
 5. The method of claim 3, wherein the forming thecircuit board carrier having the first elongate rail comprises locatinga first laterally and longitudinally extending flange along at least aportion of an outer edge of the first elongate rail, and wherein theforming the circuit board carrier having the second elongate railcomprises locating a second laterally and longitudinally extendingflange along at least a portion of an outer edge of the second elongaterail.
 6. The method of claim 5, further comprising forming at least afirst set of indexing holes extending transversely through at least oneof the first and second laterally and longitudinally extending flanges.7. The method of claim 6, wherein the forming the at least the first setof indexing holes comprises configuring indexing holes with distancestherebetween that are identical and standardized for use inpreconfigured semiconductor device assembly processing equipment.
 8. Amethod of fabricating a carrier for securing at least one circuit board,the method comprising: forming a circuit board carrier having a firstelongate rail defining a first elongate groove therein, a secondelongate rail substantially parallel to the first elongate rail defininga second elongate groove therein, and at least one cross-memberconnecting the first elongate rail to the second elongate rail with thefirst elongate groove facing the second elongate groove; configuring thefirst elongate groove to receive a first edge of the at least onecircuit board and the second elongate groove to receive a second,opposing edge of the at least one circuit board; configuring the firstand second elongate grooves in mutually facing relationship tosubstantially constrain non-longitudinal movement of the at least onecircuit board when the first and second edges thereof are respectivelyreceived therein; and positioning at least a portion of first circuitboard retaining member between the first and second elongate grooves byan interference fit proximate a first end of at least one of the firstand second elongate rails.
 9. A method of fabricating a carrier forsecuring at least one circuit board, the method comprising: forming acircuit board carrier having a first elongate rail defining a firstelongate groove therein, a second elongate rail substantially parallelto the first elongate rail defining a second elongate groove therein,and at least one cross-member connecting the first elongate rail to thesecond elongate rail with the first elongate groove facing the secondelongate groove; configuring the first elongate groove to receive afirst edge of the at least one circuit board and the second elongategroove to receive a second, opposing edge of the at least one circuitboard; configuring the first and second elongate grooves in mutuallyfacing relationship to substantially constrain non-longitudinal movementof the at least one circuit board when the first and second edgesthereof are respectively received therein; pivotally mounting a firstend of a first circuit board retaining member proximate a first end ofthe first elongate rail; positioning a retaining peg proximate a firstend of the second elongate rail and extending from a surface of thesecond elongate rail; and securing a hooked portion at a second end ofthe first circuit board retaining engaging the retaining peg.
 10. Themethod of claim 9, wherein the securing the hooked portion comprisesconfiguring the hooked portion to be engageable with the retaining pegupon rotation of the first circuit board retaining member intosubstantially transverse alignment with the first and second elongaterails.
 11. A method of securing a circuit board to a carrier, the methodcomprising: providing a circuit board carrier having a first elongaterail defining a first elongate groove therein, a second elongate railsubstantially parallel to the first elongate rail defining a secondelongate groove therein, and at least one cross-member connecting thefirst elongate rail to the second elongate rail with the first elongategroove facing the second elongate groove; inserting at least one circuitboard between the first and second elongate rails so that first andsecond opposing edges of the at least one circuit board are respectivelyreceived within the first and second elongate grooves so as tosubstantially constrain non-longitudinal movement of the at least onecircuit board; substantially securing the at least one circuit boardbetween the first and second elongate rails against longitudinalmovement thereof; positioning a retaining peg proximate the first end ofthe second elongate rail and extending from a surface of the secondelongate rail and; providing a first circuit board retaining memberproximate a first end of at least one of the first and second elongaterails, the first circuit board retaining member having a hooked portionproximate an end thereof for engaging the retaining peg andsubstantially retaining the at least one circuit board.
 12. The methodof claim 11, wherein the having the hooked portion comprises configuringthe hooked portion to be engageable with the retaining peg upon rotationof the first circuit board retaining member into substantiallytransverse alignment with the first and second elongate rails.
 13. Amethod of fabricating a carrier for securing at least one circuit board,the method comprising: forming a circuit board carrier having a firstelongate rail defining a first elongate groove therein, a secondelongate rail substantially parallel to the first elongate rail defininga second elongate groove therein, and at least one cross-memberconnecting the first elongate rail to the second elongate rail with thefirst elongate groove facing the second elongate groove; configuring thefirst elongate groove to receive a first edge of the at least onecircuit board and the second elongate groove to receive a second,opposing edge of the at least one circuit board; configuring the firstand second elongate grooves in mutually facing relationship tosubstantially constrain non-longitudinal movement of the at least onecircuit board when the first and second edges thereof are respectivelyreceived therein; and securing a first circuit board retaining member toat least one of the first and second elongate rails, the first circuitboard retaining member extending between the first and second elongaterails.
 14. The method of claim 13, further comprising securing a secondcircuit board retaining member to at least one of the first and secondelongate rails, the second circuit board retaining member extendingbetween the first and second elongate rails.
 15. A method of fabricatinga carrier for securing at least one circuit board, the methodcomprising: forming a circuit board carrier having a first elongate raildefining a first elongate groove therein, a second elongate railsubstantially parallel to the first elongate rail defining a secondelongate groove therein, and at least one cross-member connecting thefirst elongate rail to the second elongate rail with the first elongategroove facing the second elongate groove; configuring the first elongategroove to receive a first edge of the at least one circuit board and thesecond elongate groove to receive a second, opposing edge of the atleast one circuit board; configuring the first and second elongategrooves in mutually facing relationship to substantially constrainnon-longitudinal movement of the at least one circuit board when thefirst and second edges thereof are respectively received therein; andforming a first board retaining member on one end of at least one of thefirst and second elongate rails, wherein forming the first boardretaining member comprises forming a biasing member.
 16. A method offabricating a carrier for securing at least one circuit board, themethod comprising: forming a circuit board carrier having a firstelongate rail defining a first elongate groove therein, a secondelongate rail substantially parallel to the first elongate rail defininga second elongate groove therein, and at least one cross-memberconnecting the first elongate rail to the second elongate rail with thefirst elongate groove facing the second elongate groove; configuring thefirst elongate groove to receive a first edge of the at least onecircuit board and the second elongate groove to receive a second,opposing edge of the at least one circuit board; configuring the firstand second elongate grooves in mutually facing relationship tosubstantially constrain non-longitudinal movement of the at least onecircuit board when the first and second edges thereof are respectivelyreceived therein; and forming a first board retaining member on one endof at least one of the first and second elongate rails, wherein formingthe at least one cross-member comprises positioning the at least onecross-member substantially between ends of the first and second elongaterails.
 17. The method of claim 16, further comprising forming a secondboard retaining member to a second end of the at least one of the firstand second elongate rails.
 18. The method of claim 17, wherein formingthe second board retaining member comprises forming a biasing member.19. The method of claim 17, wherein the forming the circuit boardcarrier having the first elongate rail comprises locating a firstlaterally and longitudinally extending flange along at least a portionof an outer edge of the first elongate rail, and wherein the forming thecircuit board carrier having the second elongate rail comprises locatinga second laterally and longitudinally extending flange along at least aportion of an outer edge of the second elongate rail.
 20. The method ofclaim 19, further comprising forming at least a first set of indexingholes extending transversely through at least one of the first andsecond laterally and longitudinally extending flanges.
 21. The method ofclaim 20, wherein forming the at least the first set of indexing holescomprises configuring indexing holes with distances therebetween thatare identical and standardized for use in preconfigured semiconductordevice assembly processing equipment.
 22. A method of fabricating acarrier for securing at least one circuit board, the method comprising:forming a circuit board carrier having a first elongate rail defining afirst elongate groove therein, a second elongate rail substantiallyparallel to the first elongate rail defining a second elongate groovetherein, and at least one cross-member connecting the first elongaterail to the second elongate rail with the first elongate groove facingthe second elongate groove; configuring the first elongate groove toreceive a first edge of the at least one circuit board and the secondelongate groove to receive a second, opposing edge of the at least onecircuit board; configuring the first and second elongate grooves inmutually facing relationship to substantially constrain non-longitudinalmovement of the at least one circuit board when the first and secondedges thereof are respectively received therein; forming a first boardretaining member on one end of at least one of the first and secondelongate rails; and positioning a retaining peg proximate a first end ofthe second elongate rail and extending from a surface of the secondelongate rail, wherein forming the first board retaining membercomprises pivotally mounting the first board retaining member proximatea first end of the first elongate rail and forming a hooked portion at asecond end of the first board retaining member for engaging theretaining peg.
 23. The method of claim 22, wherein forming the hookedportion comprises configuring the hooked portion to be engagable withthe retaining peg upon rotation of the first board retaining member intosubstantially transverse alignment with the first and second elongaterails.
 24. A method of securing a circuit board to a carrier, the methodcomprising: providing a circuit board carrier having a first elongaterail defining a first elongate groove therein, a second elongate railsubstantially parallel to the first elongate rail defining a secondelongate groove therein, and at least one cross-member connecting thefirst elongate rail to the second elongate rail with the first elongategroove facing the second elongate groove; inserting at least one circuitboard between the first and second elongate rails so that the first andsecond opposing edges of the at least one circuit board are respectivelyreceived within the first and second elongate grooves so as tosubstantially constrain non-longitudinal movement of the at least onecircuit board; substantially securing the at least one circuit boardbetween the first and second elongate rails against longitudinalmovement thereof; providing a first board retaining member on one end ofat least one of the first and second elongate rails for substantiallyretaining the at least one circuit board; and positioning a retainingpeg proximate a first end of the second elongate rail and extending froma surface of the second elongate rail, wherein providing the first boardretaining member comprises forming a hooked portion at a second end ofthe first board retaining member for engaging the retaining peg andretaining the at least one circuit board.
 25. The method of claim 24,wherein forming the hooked portion comprises configuring the hookedportion to be engageable with the retaining peg upon rotation of thefirst board retaining member into substantially transverse alignmentwith the first and second elongate rails.